Evaluation of thermal conductivity from Green's functions molecular dynamics

• Grant number: 20/03387-7
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2021
• End date: March 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Vitor Rafael Coluci
• Grantee: Vitor Rafael Coluci
• Host Institution: Faculdade de Tecnologia (FT). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil
• Associated researchers: Socrates de Oliveira Dantas ; Vinod Kumar Tewary

Abstract

Thermal conductivity is a crucial property for developing applications in energy harvesting, thermal dissipation, and quantum computing. One of the most used approach to predict the thermal conductivity is by the analysis of the dissipation of the heat flux fluctuations in equilibrium molecular dynamics simulations, by integrating the heat flux auto-correlation function. To achieve the convergence of the auto-correlation function and accurate predictions, long simulations of the order of 100 ns are usually required. Carrying out such simulations using conventional molecular dynamics is a formidable task even for modern computers. Green's function molecular dynamics (GFMD) simulations have been proven to extend the simulation time scale by 6-8 orders of magnitude (pico to microseconds) in certain idealized non-linear elastic problems. In this project, we aim to evaluate the accuracy of GFMD in predicting thermal conductivity. We will apply the Green-Kubo technique within GFMD simulations and study the effect of simulation parameters such as time-step size and correlation time on the convergence of the auto-correlation function. The thermal conductivity will be calculated for one-dimensional systems with and without defects. Because GFMD can provide more accurate trajectories in the phase space, we expect it can reduce the averaging and time integration errors in estimations of the thermal conductivity. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COLUCI, V. R.; DANTAS, S. O.; TEWARY, V. K.. Accelerated causal Green?s function molecular dynamics. COMPUTER PHYSICS COMMUNICATIONS, v. 277, p. 7-pg., 2022-08-01. (20/03387-7, 10/50646-6)